Info on Reshevsky from Chess Life ( Nov.2011 ). In 1990, at age 79, he played in the US Open held in Jacksonville. He went 7 out of 9 there, including a Draw against IM John Donaldson. By this time he may well have forgotten more about Chess than most players could ever hope to learn lol.

An interesting story. Back in the 80s when I first started to play against serious players I asked a local master if Reshvesky, who was in his 80s at that time, was any good still since he was about 2300 at the time

2300? No, you're way off. The last rating for Sammy, 1991, is 2415 FIDE according to my megabase.

it was USCF rating he was fairly inactive at the time and didnt play many FIDE events but I clearly remember 2300ish ( wonder if i can dig up old uscf rating lists sometime at the club) Which is why I brought up the question to the master. its been a few decades so the exact timing I am not sure of but the rating is irrelevent anyway...

Comparing performance capabilities between someone who did something seriously their whole life and was very, very good at it with someone who at most dabbled in the same area as they age is sophistry and fully misses the point.